UK Flow Battery To Be Tested In US

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Wind and solar power are out, according to this year’s abrupt shift in federal energy policy. However, energy storage is in. The US Department of Energy is continuing to support new utility-scale battery technologies that will help accelerate the renewable energy transition, and the UK flow battery startup Invinity Energy Storage Systems is among those tapped for an assist.

The Long, Slow Rise Of The Flow Battery

Lithium-ion batteries have carried much of the energy storage water for wind and solar. However, renewable energy advocates have long advocated for new energy storage systems that can deliver more kilowatts, more economically, over longer periods of time.

That’s been a tough row to hoe. The century-old technology of pumped hydropower energy storage continues to dominate the long duration field in the US up to the present day. Even though pumped storage is limited by circumstances of geography and water availability, it accounts for about 97% of all long duration energy storage in the US, spread over 42 sites providing a combined total of 23 gigawatts in storage capacity.

Alternatives are beginning to emerge, with flow batteries among the contenders. Flow batteries generate a charge by leveraging the movement of two chemically tuned liquids, making scale-up a relatively simple matter of using larger tanks to hold the solutions.

Of course, the devil is in the details. The origins of flow battery technology date back even longer than pumped storage, but an economical pathway to scale-up eluded flow battery enthusiasts for many years. The first flow battery was patented in 1879, deploying zinc and bromine. The field was pretty quiet until the 1970s when new formulas began to emerge, including an iron-chromium combination proposed by a NASA scientist.

Zinc-bromine also experienced a revival in the 1970s. Exxon was developing energy storage technology around that time, leading to a short-lived zinc-bromine partnership with Sandia National Laboratories in the 1980s.

UK Sends A Vanadium Flow Battery Love Letter To The US

Vanadium is another flow battery formula with roots in 1980s research. Among other advantages, vanadium* streamlines the supply chain. It can exist in two different ionic states, making it suitable for both sides of the flow battery equation. *Not to be confused with vibranium.

Among the vanadium flow battery innovators to cross the CleanTechnica radar is the UK firm Invinity Energy Systems. The Energy Department has also taken notice. In May of 2024, the agency engaged Invinity to install its flow batteries at six sites in the US on a demonstration basis, under the code name “Mistral.”

As of late last year, the project was still active. “In support of the overall program, the Energy Department’s Pacific Northwest National Laboratory is hosting one of the batteries for a 10-year demonstration period,” CleanTechnica reported in December of 2024. Rural electric cooperatives in the Midwest and Southeast were tasked with hosting the other five.

For its part, Invinity has not been waiting around for the paint to dry. In February of this year, Invinity announced a new partnership with the firm Frontier Power, aimed at ramping up its flow battery manufacturing operation in Scotland with an eye on exporting the technology around the world in addition to deploying it locally.

US Energy Department Still Hearts Energy Storage

In the meantime, PNNL has also been keeping itself busy. On December 9, the lab announced that its new Grid Storage Launchpad test facility is now up and running. GSL marks a key milestone in the Energy Department’s efforts to support new utility-scale storage systems, enabling researchers to assess batteries up to 100 kilowatts. That’s a significant step beyond current testing facilities.

“To date, researchers have been limited to testing smaller battery systems (less than 10 kilowatts),” PNNL explains. “These systems often lack the more sophisticated controls and complexity seen in larger-scale systems.”

“With the 100 kW scale testing capability at GSL, testing and validation of new technologies can be done at a scale ready for grid-scale usage,” the lab adds.

PNNL has tapped an Invinity flow battery to give the new Grid Storage Launchpad a workout. “For the next year, Invinity’s battery will be subjected to an in-depth testing regime under real-world conditions,” PNNL elaborated, citing the delivery of peak shaving services and frequency regulation as examples.

All This And Marine Energy, Too

PNNL is already accepting applications from other energy storage innovators to test their wares at the Grid Storage Launchpad. In addition to supporting flow battery technology, the testing program will help accelerate the use of other new grid-scale energy storage systems, with the ultimate result of supporting more wind and solar power in the US.

That’s an interesting twist, considering the current state of federal energy policy. To make things even a little more interesting, energy storage is not the only form of cleantech embraced by the White House. Biomass, geothermal, and hydropower have also gotten the thumbs-up, along with marine energy.

Marine energy is where the paths of Invinity and the Energy Department have the potential to cross again. Marine energy refers to devices that harvest the kinetic energy of waves, tides, or currents. The marine energy field has a long way to go before mass adoption. However, activity has been accelerating in recent years (see lots more marine energy background here).

Marine energy has also begun to intersect with the green hydrogen industry, and that’s where Invinity comes in. The company has been contributing its flow battery to a green hydrogen project in Orkney, Scotland, that leverages tidal energy, hosted by the European Marine Energy Centre.

The project launched in 2020 and Invinity posted an update just last week, on December 3. It looks like all that hard work has paid off. “Invinity Energy Systems was delighted to note that its customer, the European Marine Energy Centre (EMEC), successfully completed a world-first demonstration combining tidal power, vanadium flow battery (VFB) storage and hydrogen production at its facility in Orkney, Scotland,” Invinity enthused.

“Led by EMEC, Invinity’s 1.8 MWh VFB was successfully integrated alongside Orbital Marine Power’s O2 tidal turbine and a 670 kW ITM Power electrolyser at EMEC’s onshore site on the island of Eday,” Invinity elaborated.

“Maintaining a stable power supply to an electrolyser is key to the production of green hydrogen, which is why EMEC chose Invinity’s VFBs to support this project,” Invinity added, with green hydrogen referring to hydrogen gas pushed from water by an electrical current reacting with a catalyst.

The demonstration project also provided insights into the potential for deploying automation to optimize the integrated system with other tidal energy projects. In a press statement, the CEO of Orbital Marine Power, Andrew Scott, underscored the reason why marine energy continues to be a focus of US Energy Department attention.

“Tidal energy offers a predictable source of renewable power,” Scott explained. “By maximising generation through battery storage, we minimise curtailment and enable industrial offtake that can achieve higher decarbonisation, creating new markets for tidal energy and providing valuable services like grid balancing.”

What do you think, will the combination of marine energy and energy storage intersect in the US? At the present time the domestic green hydrogen industry is on life support, but after all, US presidents come and go, while the tides go on forever.

Photo: Vanadium flow battery technology will be the first to take advantage of a new energy storage test facility hosted by the US Department of Energy’s Pacific Northwest National Laboratory (courtesy of PNNL).